Thanks for all the advice, I am not looking for keeping the battery fully charged the whole time I am camping just extend the life of it an extra night or two, we really don't use much electricity just the water pump, cassette toilet, and lights at bed time and if hot enough a bunk end fan or two. It would have to be almost snowing before I would think of using the furnace.
I always carry an extra battery in the storage trunk but I am hoping to avoid having to swap batteries in the dark like the last time. I mainly bought it to help keep up the battery on my old pickup I rarely drive but figured I would try it out with the pop up since I have it.
I will figure out a couple of Bungee cords to secure it on the roof with something to prop it up with. We will be about as far north in the continental US you can get so I doubt I could get an optimal angle without some sort of brackets.
Thanks for the input
Wildcat